Stephen Merchant is one half of the UK's most successful comedy duo - and not just in terms of TV series franchised, movies produced and appeared in, Baftas and Golden Globes won. He and Ricky Gervais are among the richest comedians in the world: US website CelebrityNetWorth has Gervais worth roughly £50 million and Merchant a cool £22 million. And yet he still can't get a girlfriend.